No. 01 10/09 No. 08 INTERNATIONAL FISCHER NEWSLETTER Coating Thickness Material Analysis Microhardness Material Testing «editorial» Dear Reader, We are pleased to be able to send you the latest issue of our FISCHERSCOPE newsletter. Electronic devices have become an indispensable part of our daily life. In order to ensure they have a long working life, it is a good idea to check production processes for coatings carefully. To help you with this, Helmut Fischer would like to present the new devices for printed circuit board measurement. Even the smallest structures can be measured using XDV -µ series devices. The hardness of very thin gold coatings can also be measured accurately using the PICODENTOR ; this provides important additional information for lots of coating manufacturers. Another issue at the moment is checking the realness of gold bars and coins, as the price explosion of precious metals has caused the production of fake gold and silver goods to boom. An increasing number of counterfeit coins and bars have appeared in recent times with the SIGMASCOPE GOLD, Fischer has a new instrument which offers you a nondestructive, simple and very fast way of checking the realness. Please refer to the last page in this regard. We hope you can find a little bit of time to read the different articles and look forward to receiving any questions or suggestions you may have. With kind regards, Walter Mittelholzer CEO Helmut Fischer Holding AG Helmut Fischer AG Marcel Koch Marketing Manager Helmut Fischer AG «closer examination» Using X-ray fluorescence for fast, reliable gold analysis in the gold-buying industry The economic crisis has coincided with historically high gold prices to boost the importance of socalled «cash for gold» businesses. Because the buyer usually has only a few minutes to estimate the value of gold items presented for sale, methods like touchstone analysis are often used: Although this test severely scratches the piece it is still not 100% reliable. The industry demands a precise, quick and foolproof method for testing gold content that is, above all, nondestructive. Figure 1: Various items potentially presented for Besides the weight, the gold content of an object determines its sale to gold buyers. value. The commonly-used analysis methods pose different disadvantages for retail buyers of personal gold items: Fire assaying is time consuming and relies on chemical processes, and despite the fact that touchstone analysis also requires acids for testing, the results are still not always reliable. Because both methods damage the item in varying degrees, neither really meets the needs of the industry. However, X-ray fluorescence analysis (XRF) offers a non-destructive method for quick material analysis and coating thickness measurement on jewellery, watches and other precious metal products; FISCHER s XRF instruments are simple to use, even for non-technicians. The FISCHERSCOPE X-RAY XAN 220 enables precise and reliable determination of gold and platinum content even under challenging circumstances. Fast and easy-to-use, the XAN 220 features excellent long-term stability and rarely ever Figure 2: Fast and non-destructive requires calibration. measurment of a gold wristband with the FISCHERSCOPE X-RAY XAN 220. Advantages: Fast: results in less than a minute Easy: single-button functions Reliable and accurate: intelligent WinFTM software prevents measurement errors Robust and stable: factory calibrated, no timeconsuming re-adjustments
«information from practice» Measurement technology for the printed circuit board industry: the new FISCHERSCOPE X-RAY PCB device series The inspection of the coating on printed circuit boards during the production process or in the incoming goods inspection is an area where Helmut Fischer has already been successfully active for some time with a wide range of devices and procedures. There are constant new requirements for measurement technology due to Figure 1: With the XDV -µ PCB device, even further developments in the thinnest layers on the smallest structures production technology. can be measured. In this case, the ever-decreasing thicknesses of precious metal coatings and the ever-smaller structures that need to be measured on the printed circuit board and printed circuit board sizes of up to 24 x 21 (~ 610 mm x 530 mm) pose a particular challenge. Accommodating these specifications was a trigger for Helmut Fischer to develop a new X-RAY device series specifically for the printed circuit board industry. The following table provides an overview of the new devices. All of these devices offer simple and secure handling of large printed circuit boards. In addition, all devices are equipped with appropriate support stages, making it possible to measure even the edges of large and rigid (as well as flexible) printed circuit boards easily. The various device models differ in terms of measuring spot size, detector type and XY table: for the user this means various measurement options regarding structure size, coating thickness and automation. XULM PCB The X-ray source on the XULM PCB is located beneath the printed circuit board, i.e. the board will be measured from the bottom Figure 2: Coatings on printed circuit boards can be measured quickly and reliably using the new FISCHERSCOPE X-RAY PCB series. up. As a result, flat samples such as printed circuit boards will always be automatically positioned at the correct measuring level, meaning that it is no longer necessary to refocus before each measurement. The XULM PCB can therefore be used for the simple, fast and cost-effective measurement of large printed circuit boards. XDLM PCB An open unit concept has been implemented in the XDLM PCB to ensure easy handling and greater flexibility. There is no cover which encloses the material and the measuring head and which needs to be opened before each measurement. The X-ray source is above the printed circuit board, and the distance between the measuring head and the support stage is fixed, meaning that it is possible to measure printed circuit boards of all used thicknesses, but there is no danger for the operating personnel. The XDLM PCB 200 features a fixed sample stage with manual tongue function. This makes quick pre-positioning possible, even on large circuit boards, through the use of a laser pointer. Instruments Detector Apertures Primary filter Support stage XY table XULM -PCB Proportional counter tube Fixed Ø 0.1mm Others optional Fixed 800 x 630 mm 1200 x 630 mm with extension XDLM - PCB 200 Proportional counter tube Fixed Ø 0.1mm Others optional Fixed 600 x 600 mm 1200 x 900 mm with extension XDLM - PCB 210 Proportional counter tube Fixed Ø 0.1mm Others optional Fixed 600 x 600 mm 450 x 300 mm XDLM - PCB 220 Proportional counter tube x4 exchangeable x3 exchangeable 600 x 600 mm 450 x 300 mm XDV -µ-pcb Si-Driftdetektor Polycapillary, approx. 20µm FWHM with Mo-K-alpha x4 exchangeable 600 x 600 mm 450 x 300 mm FISCHERSCOPE No. 08
The XDLM PCB 210 is equipped with a programmable XY table with 450 x 300 mm travel range and tongue function. This means that even large printed circuit boards can be measured automatically. Even greater flexibility is offered by the XDLM PCB 220, which also includes 4 exchangeable apertures and 3 exchangeable primary filters. The XULM PCB and XDLM PCB devices offer a good solution for a majority of measuring tasks for printed circuit boards. However, there are restrictions for very thin layers. This has the following meaning for the example of an Au coating: Layer thicknesses of over 100 nm can be measured without restriction; for layer thicknesses of less than 100 nm, however, it is necessary to have calibration with a standard which matches the structure and thickness of the individual layers (Au, Ni, Cu) of the printed circuit board to be measured. Layer thicknesses of less than 50 nm can only be reliably measured with devices with a semiconductor detector. XDV -µ PCB The XDV -µ PCB also uses the open unit concept already described for the XDLM PCB, as a well as a programmable XY table with 450 x 300 mm travel range. The use of a poly-capillary X-ray optic makes it possible to generate very high intensities on a very small measuring spot. Together with the Si drift detector, this means that the requirements are met to allow measuring of the very thin layers in the smallest structures. Using the example of the Au coating, this means: with the XDV -µ PCB, layer thicknesses of just a few nm can still be reliably measured. The XDV -µ PCB completes the PCB device series and meets the highest requirements for the measurement of coating thicknesses and structural sizes. This means that the devices presented here from the new FISCHERSCOPE X-RAY PCB family cover a wide range of the applications in the printed circuit board industry. More information: www.pcb-xray.de Dr. Bernhard Nensel Figure 3: The XULM PCB can also easily measure external positions on large printed circuit boards.. Figure 4: The XDLM PCB has an open unit concept. This means that it is easy to achieve large support stages and large XY travel ranges. «closer examination» The XDV -µ: an X-RAY device optimised for the analysis of the smallest structures The progress in miniaturisation, particularly in electronics, but also in other areas of industry, presents constant new challenges for measuring device manufacturers. The customers want things to be smaller, quicker and more precise. These means that even more accurate measurement results need to be produced with smaller measuring points and shorter measurement times. With the triedand-tested aperture technology in the X-RAY devices, there are fixed limits on the lateral resolution and the measuring time, which are around 50 100 µm aperture size, in which case it must be considered that there will be long measurement times. The use of polycapillary «lenses» is a promising alternative to this. Fine glass capillaries focus the X-rays on the sample using total reflection. These X-ray optics allow for a high primary X-ray intensity on the sample to be examined whilst still having very small measurement point diameters. Figure 1: The new XDV -µ-wafer device is equipped with a very fine focusing polycapillary lens and is optimised for the analysis of layers on wafer pads. No. 08 FISCHERSCOPE
Figure 2: A distribution map of the layer thicknesses is produced via the 16 pads in the centre. Figure 5: Selectively gold-plated plug-in contacts, the gold layer thickness was inspected across the length of the line scan in the area of the marking. Helmut Fischer GmbH currently has three different devices available which are equipped with these innovative X-ray optics. Firstly, the Standard-XDV -µ, and also a XDV -µ PCB and the XDV -µ WA- FER, which was designed for the semiconductor industry. The Standard XDV -µ and the PCB device are equipped with standard polycapillaries. These X-ray optics allow for a measurement point size of 20 µm (full width at half maximum of the intensity for Mo-Kalpha) with an intensity of >10 5 cps in copper. The XDV -µ WAFER is equipped with a lens with even better focussing power, which allows for a measurement point diameter of 10 µm. With this device it is possible, for example, to analyse the layers of Au/Pd/Ni/ Cu/Si wafer on pads of 50 µm diameter and even to check the lateral layer thickness homogeneity of pads. Figure 2 shows pads of 50 µm diameter on a silicon wafer. The layer structure is Au/Pd/Ni/Cu/wafer, the distance between the pads is 25 µm. A distribution pattern of the Au thickness on these pads (Figure 3) confirms that there are several measurement points on the pad and that the individual pads are clearly separated. Figure 3: Map of the Au layer thickness of the pads in Fig. 2 There are several measurement points on the pad, as shown by the relatively flat area of the maximum thickness. The distribution was produced using a polycapillary with 20 µm FWHM. The map in figure 3 was produced using our standard capillaries. The plateau is even clearer if we use a high-resolution polycapillary (Figure 4), which allows for a measurement point of 10 µm. An example for the use of a layer thickness measuring device with polycapillaries in the area of the contacts and their coatings is provided in Figure 5. The plug-in contacts are very thin, have been selectively coated with gold and their ends go into small cylindrical structures. The Au thickness on the end of the plug can no Figure 4: With a capillary with better focusing (10 µm FWHM), the plateau of the maximum thickness values on the pads is more distinct and there are more measurement points on the pad. Figure 6: Change in the gold layer thickness from the rounded tip of the plug to the base of the plug-in contact (in Fig. 5 from bottom to top). FISCHERSCOPE No. 08
longer be reliably measured in a practical amount of time using apertures. The Au thickness distribution along the strip can only be optimally inspected using a polycapillary lens (Figure 6). Clocks (Figure 7) are the embodiment of delicate, precision components. In this area our XDV -µ devices offer new possibilities for the characterisation of the coatings. In short: Whenever there are thin layers combined with small measurement points and short measurement times, the XDV -µ is the right device. Dr. Wolfgang Klöck Figure 7: Clock components are tiny, but also have to be checked for quality features such as composition and layer thickness. «closer examination» Determination of mechanical properties in the nanometre range with the PICODENTOR HM500 In times when raw material prices are rising, increasingly thin layers are being used even in the electronics industry. Precise and reliable measurement technology is needed in order to determine the mechanical properties, for example of gold layers on printed circuit boards or plug-in contacts with layer thicknesses of down to just a few 100 nm, The thin layers of gold used on printed circuit boards or plug contacts (Figure 1) have various roles. They are used as corrosion protection, to improve soldering capacity and as protection against wear. Figure 1: Au coated printed circuit board and plug-in contacts. In order to guarantee the quality of the gold alloys, it is recommended that the mechanical properties of the layer should be determined. The procedure of the instrumented penetration test offers the ideal requirements for determining them without influencing the substrate. Due to the small diameters of the impressions, in some cases of only slightly more than 100 nm, it is no longer possible to determine the thickness of these layers visually. With the instrumented penetration test, in addition to determining the thickness, by using the plastic and/or elastic deformation it is also possible to determine other properties which determine the quality, such as the modulus of penetration. For the technical applications, such as for sliding contacts, the mechanical properties must have consistent values. Figure 2a shows the average values of several measurements for a 0.5 µm (blue) and a 0.2 µm (red) thick gold layer, which were measured with a maximum force of 200 µn and 50 µn respectively. In order to be able to compare the samples, the length of time for which the force was applied was adjusted so that the two loading and relief curves display the same gradients. Figure 2b shows the respective progression of the Martens hardness. The two samples display an almost identical hardness curve. On the basis of the standard deviation (variation coefficient of approx. 5%), it is possible to see the precision with which parameters the can be determined even with these low layer thicknesses. The measurements show that the gold layers on the surface have a slightly higher Martens hardness. No. 08 FISCHERSCOPE
0,06 Depth (µm) 4500 Hardness (N/mm A 2) 4000 0,05 3500 0,04 3000 2500 0,03 2000 0,02 1500 1000 0,01 500 0 0 0,05 0,1 0,15 0,2 0,25 Force (mn) 0 0 0,01 0,02 0,03 0,04 0,05 0,06 Depth (µm) Figure 2a: Force penetration depth diagram incl. Standard deviation of a 0.2 µm (red) and a 0.5 µm (blue) thick Au layer. Figure 2b: Martens hardness (HM) incl. Standard deviation of a 0.2 µm (red) and a 0.5 µm (blue) thick Au layer. In order to be able to achieve measurements with penetration depths of a few nanometres, the samples must display an almost perfectly smooth surface. Only then can the technical potential of the PICODENTOR be fully used with its high power and displacement resolution. The high quality of the measurement results is also a result of the high reproducibility of the automatic determination of the indentor reference point. In addition, the high mechanical and thermal stability of the granite base allows for the possibility to carry out measurements on these thin coatings. When you need to determine the mechanical properties of thin gold layers with a high level of precision, PICODENTOR HM500 from FISCHER is the right device. Dr. Tanja Haas, Dr. Bernd Binder «information from practice» Measuring Thick Pipeline Coatings using probe FA100 In the oil and gas industry, it is common to transport the liquid or gaseous goods through undersea pipelines. Insulation is not only necessary to avoid thermal losses, since the oil is mixed with hot steam to improve its fluid properties, but also to protect the pipe from the extreme temperatures (e.g. in the polar regions), high pressure and corrosive waters found at the bottom of the ocean: Any penetration of the coatings can eventually result in leakage and environmental disaster. Figure 1: Calibrating the FA100 probe against an uncoated pipeline section using a Fischer standard. BSR Pipeline Services, part of Tata Steel have been coating pipelines for the oil and gas industry for approximately 25 years. On the oil pipelines, propylene coatings serve a multitude of important purposes including corrosion prevention and insulation, but they are expensive. In order to ensure appropriate thickness for guaranteeing performance without wasting valuable material, the application process needs to be controlled carefully. Therefore, for both corrosion prevention and insulation, the pipes are typically enclosed in one or more layers (often up to 100 mm thick in total) of polypropylene, a highly resilient thermoplastic polymer that can withstand the harsh deep-sea conditions. To ensure the layers are properly applied sufficiently thick but without wastage or delamination rigorous quality inspections must be performed using a highly accurate instrument that can measure coatings of such dimensions. Especially for these demanding requirements, FISCHER has developed the FA100 probe, which fully covers the thickness range of up to 100 mm. The FA100 can be connected to the handheld instruments ISOSCOPE or DUALSCOPE of the FMP family, allowing mobile use wherever needed. The handy FMP gauges are available with either a touchscreen or even more robust conventional buttons. FISCHERSCOPE No. 08
The FA100 plus FMP combination easily handles multi-layer structures without negative influence, irrespective of coating material type. This ability help the FA100 achieve the expected accuracies of better than 1mm. The results in Table 1 below are taken from measurements taken with calibrated measurement chain. 7 readings were taken with each block and the average value for each block is recorded in Table 1. Mean Value 59.88 mm Standard Deviation 0.073 mm Co-efficient of Variation 0.1 % Min Value 59.8 mm Max Vale 60.0 mm Range 0.253 mm Table 2: Results from pipeline inspection with FA100 probe and DUALSCOPE FMP100. The measurements also show that the accuracy of the probe to be better than 1mm, with good repeatability. For best accuracies, the probe would be calibrated against different diameter pipe sections. Each calibration could be saved in a separate application. For different diameter pipes, the user can easily select the appropriate application as seen in fi g2. seconds. If required, an array of measurements on the pipelinesurface, showing thickness variations along the tube-axis and/or along the circumference of the tube can be easily arranged within a few minutes. The results from any measurements can then be viewed statistically on the instrument or downloaded to be viewed on Fischer DataCenter software which allows users to evaluate and archive data or to generate reports. Block Actual Thickness values of standards (mm) Measured thickness Average (mm) Measured Standard deviation (mm) Nominalactual value difference (mm) 1 14.20 14.51 0.12 0.31 2 18.44 18.47 0.01 0.03 3 25.53 25.93 0.09 0.40 4 32.64 32.98 0.12 0.34 5 39.73 39.84 0.07 0.11 6 58.17 58.43 0.17 0.25 7 76.66 76.54 0.19 0.12 8 83.57 84.01 0.11 0.44 Table 1: Thickness Measurements using standards on a tube with 270 mm outer diameter. Figure 3: Coating thickness measurement on a pipeline section with the FA100 probe and DUALSCOPE FMP100 instrument. Unlike ultrasonic probes the FA 100 doesn t require any couplant medium. Also, wrapped multi-layer coating material will not influence the FA 100-measurement (as it is known for ultra-sonic methods). The metallic tube core can be either ferromagnetic steel or stainless steel but also aluminium or copper, as the basic principle for the probe FA 100 is eddy current. The ability to measure coatings up to 100 mm accurately and precisely is what attracted BSR Coatings to the FA100 and DUAL- SCOPE FMP100. This will enable them to monitor their processes more closely and ensure that the pipelines are not over-coated whilst still meeting tolerances and thus will save costs on this process. Figure 2: DUALSCOPE FMP100 screen showing different applications, each with its own corrective calibration for each diameter pipe section for better accuracy. Peter Ho M.Sc. Fischer Instrumentation (GB) Ltd Table 2 below shows measurements taken from the coating on the pipe section. The results demonstrate the precision and consistency of the FA100 probe. Once the measuring system is calibrated on the corresponding pipe diameter, each measurement is only a matter of No. 08 FISCHERSCOPE
«information from practice» Testing the genuineness using electrical conductivity Figure 1: True or fake? Gold Bullions and Coins. The instruments of the X-RAY product line operate according to the X-ray fluorescence analysis (XRFA) method and can determine the composition of jewellery, coins, bullions and other items quickly. Conductivity measurement using SIGMASCOPE GOLD The electrical conductivity of gold bullions and of all common coins is known. Counterfeits have inclusions on the inside, made, for example, of tungsten. These inclusions change the electrical conductivity significantly. Thus, using a comparative measurement of the electrical conductivity allows for a reliable, quick and non-destructive identification of counterfeits. Because of the price explosion in precious metals, the production of counterfeit gold and silver goods has developed into a booming industry. Lately, more and more counterfeit coins and bullions have surfaced. This has led to uncertainty in the market and many investors have become leery. Institutional and private investors want to be certain that they do not invest their assets in counterfeit coins or bullions. With FISCHER measuring instruments, you will find any imitation quickly, reliably and non-destructively. With the SIGMASCOPE GOLD, FISCHER offers instruments that are ideally suited for determining the conductivity from precious metal coins up to large gold bullions. Figure 3: Testing a fine gold bullion The instruments work possible even through a protective foil. non-destructively and utilise the eddy current method according to DIN ISO 21968. The phase-sensitive measurement signal evaluation allows for contactfree determination of the electrical conductivity even under nonconducting top layers such as plastic packaging. The penetration depth of the eddy currents can be selected corresponding to the thickness of the specimen. conductivity of different coin alloys on the basis of gold-copper-alloys pure gold Ducat conductivity 875-coin gold Reichsmark Krugerrand conductivity 1. measurement range 2. measurement range 3. measurement range density gold thickness Figure 2: Electrical conductivity a positive indicator for genuineness. Destructive methods for testing the genuineness lead to a loss of value. With the product lines SIGMASCOPE GOLD and X-RAY, FI- SCHER offers two non-destructive methods that complement each other perfectly when the genuineness of precious metal coins and bullions needs to be tested quickly and accurately. The SIGMASCOPE GOLD detects counterfeit precious metal bullions and coins via electrical conductivity. They utilise the physical fact that various alloys and fine gold differ in their conductivity. Figure 4: For every bullion size the correct penetration depth to measure the electrical conductivity. www.helmutfischer.com FISCHERSCOPE No. 08